Seasonal Variation in the Population Density of the Gall Mite, Aceria doctersi (Nalepa, 1909) (Acari :Eriophyidae) Within the Leaf Galls of Cinnamomum verum (Presl.)

Aceria doctersi is a highly host specific phytophagous eriophyid mite, infesting and inducing varying numbers of pouched galls on the leaves, leaf petioles, inflorescence and the young shoots of Cinnamomum verum, one of the most economically important spice and medicinal crop. Gall formation by A. doctersi adversely affects the quality of the leaves, thereby reducing the economic utility of the plant. The present study discusses the seasonal impact on the population density of the gall mite, A. doctersi within the leaf galls of C. verum, carried out in the Calicut University Campus, Malappuram Dt. , Kerala from January, 2012 to December, 2012. The impact of temperature and humidity could be positively correlated with the population density of the mite within the leaf galls (r = 0.58, r = 0.237) whereas rainfall exerted a negative correlation (r = - 0.182). The study also sheds light on percentage of damage, relationship between size of the galls and mite population density.